Researchers at Ohio State University studied 11,700 middle-school-aged children and found even minor increases in fast food consumption were associated with poorer academic test results. Kids who eat fast food on a daily basis saw "test score gains that were up to about 20 percent lower than those who didn't eat any fast food."

"Our results show clear and consistent associations between children's fast food consumption in fifth grade and academic growth between fifth and eighth grade," researchers wrote in the study, titled "Fast Food Consumption and Academic Growth in Late Childhood." "These results provide initial evidence that fast food consumption is associated with deleterious academic outcomes among children."

Correlation may not be causation, but it's close in this case: The relationship between increased fast food intake and lower test scores held even as researchers took other factors into account, including socioeconomic status, fitness and and school quality (low-income and food-scarce communities have greater access to fast food).

It's not clear precisely why fast food may be affecting children's brains, although according to the Washington Post, a 2013 study showed that fast food is deficient in nutrients like iron, essential for the development of a child's brain.

But parents and health officials should be concerned given how much fast food American children consume. According to a 2008 study, roughly a third of kids age 2 to 11 and nearly half of those age 12 to 19 eat from a fast food restaurant daily. And fast food still accounts for roughly 13% of total calories eaten by children age 2 to 18 in the U.S.

Let's move: While we're still waiting for first lady Michelle Obama's youth fitness campaign to yield substantive results, research like the Ohio State study further bolsters arguments that childhood obesity and health are more than just part of a public health crisis. They have far-reaching consequences that affect school performance, class mobility and, now, brain function.

One possible tactic is fighting brands with brands. Major fast food names like McDonald's have a powerful presence in the lives of children — according to Fast Food Nation, a book that investigated the cultural influence of the industry, 96% of American schoolchildren can identify Ronald McDonald. That's why the first lady's "Let's Move" campaign has joined forces with Disney to reduce junk food advertisement and label healthier foods.

While fast food may conquer brain power, star power may triumph over fast food.